[lmm]

Even in the presence of QE, the value of the USD remains more-or-less stable. I can go to bed confident that it's not going to cost me $10 to get a loaf of bread tomorrow. Bitcoin isn't and won't be useful to me as a currency until its value is stable.

[pantaril]

Bitcoin is currently indeed very risky to use as store of value as the market grows quite rapidly and the exchange rate fluctuates greatly. I expect that it will improve in the future and ultimately bitcoin will be better store of value then official currencies, because the savings will not lose the value ove years due to inflation.

But fortunately bitcoin has great use even today in its current state. It is great for sending or accepting money internationaly, quickly and without ridiculous transaction fees. This is something you can't do with official curencies and is IMO big part of the success bitcoin is experiencing.